public void TestIsLoginFree2()
        {
            User        user1 = new User("Adam", "Nowak", "anowak", "Hasło1");
            User        user2 = new User("Maria", "Kowalska", "mkowalska", "Hasło2");
            List <User> list  = new List <User>();

            list.Add(user1);
            list.Add(user2);
            UserLocalDataBase uldb = new UserLocalDataBase();

            uldb.Add(user1);
            uldb.Add(user2);

            string login  = "******";
            bool   isFree = true;

            for (int i = 0; i < list.Count; i++)
            {
                if (list[i].login == login)
                {
                    isFree = false;
                }
            }

            bool result = uldb.IsLoginFree(login);

            Assert.AreEqual(isFree, result);
        }
        private void TextUpdate(object sender, RoutedEventArgs e)
        {
            if (Input_Name.Text == "")
            {
                return;
            }

            char   login1 = Input_Name.Text.ToLower()[0];
            string login2 = Input_Surname.Text.ToLower();
            int    login3 = 2;

            if (UserLocalDataBase.IsLoginFree(login1 + login2))
            {
                Input_Login.Text = login1 + login2;
                return;
            }
            while (!UserLocalDataBase.IsLoginFree(login1 + login2 + login3))
            {
                login3++;
            }
            Input_Login.Text = login1 + login2 + login3;
        }